In computer systems, data may be communicated across an optical communications link. The link may form part of a physical layer and be implemented by physical layer electronics. The physical layer defines how bits are to be transmitted and received over an optical transmission medium such as an optical fiber. For optical communications, optical transmitters may be configured to convert electrical impulses into optical signals, which may then be received by optical receivers and converted back into electrical impulses to enable data sampling. Optical communications links may be used within computing devices, e.g. to implement a systems bus, and/or to network different computing devices. As optical communications links allow high-speed communications, a serializer/deserializer (SERDES) may be used to group multiple data streams.